World History
Dissolved Empires
Empires that either don't have a convenient modern equivalent, don't have a widely recognized successor state, or are so ancient that successor states aren't relevant. The USSR actually does fall into those descriptions but it's rather insufficient to treat it as just a chapter of Russian history.
Empires are distinguished from international organizations by the number of states with effective agency. The EU is multi-polar, while the USSR was not.
Dissolved States
States that either don't have a convenient modern equivalent, don't have a widely recognized successor state, or are so ancient that successor states aren't relevant. Yugoslavia is a bit iffy but I include it anyway.
Excludes empires.
Historic Regions
Regions that have historic context, but not a historic state.
International Wars
Anglo-Spanish War and the Treaty of Seville
- Italian Wars of Independence
Thirty Years' War and the Peace of Westphalia
War of Spanish Succession and the Treaty of Utrecht
War of the Quadruple Alliance and the Treaty of the Hague